Special Topics In Physiology

Question 0

Initiate heat generating mechanisms

Answer 0

Set-point Temperature

Question 1

Regulation of body temperature is mediated by:

Answer 1

Hypothalamus

Question 2

Initiate heat loss mechanisms

Answer 2

Detected Temperature

Question 3

Shivering, Thyroid hormone production, decreased sweating, piloerection, skin vasoconstriction (alpha 1), brown fat in babies (beta 3)

Answer 3

Heat-generating Mechanisms

Question 4

Sweating, skin vasodilation, decreased heat production

Answer 4

Heat-loss Mechanisms

Question 5

What is the role of fat in terms of regulation of body temperature?

Answer 5

Insulator

Question 6

What is the role of skin in terms of regulation of body temperature?

Answer 6

Radiator System (when cold: blood vessels constrict; when hot: blood vessels dilate)

Question 7

Most of the body heat is lost through which way?

Answer 7

Radiation>Evaporation>Conduction of air>Conduction of objects

Question 8

What is the pathophysiology of fever?

Answer 8

Pyrogens➡️Increases IL-1➡️Increases Prostaglandins➡️ Increases set-point temperature in Hypothalamus

Question 9

Excessive sweating causing fainting

Answer 9

Heat Exhaustion

Question 10

High temperature causing tissue damage & impaired responses

Answer 10

Heat stroke

Question 11

High temperature secondary to the use of succinylcholine & halothane?

Answer 11

Malignant Hyperthermia

Question 12

What is the basis for muscle endurance?

Answer 12

Glycogen levels in the body

Question 13

What is the best diet for muscle glycogen recovery?

Answer 13

High carbohydrate diet

Question 14

How long does it take to recover muscle glycogen?

Answer 14

2 days (high carbohydrate diet)

Question 15

An increase in muscle strength is always due to what?

Answer 15

Increase in muscle size

Question 16

Maximal breathing capacity

Answer 16

150-170L/min

Question 17

Pulmonary ventilation during maximal exercise

Answer 17

100-110L/min

Question 18

Difference (50L/min) is used to compensate for:

Answer 18

Exercise at high altitude
Exercise under hot conditions
Abnormalities of the respiratory system

Question 19

During most strenuous exercise, muscle blood flow increase up to?

Answer 19

20x

Question 20

At maximal exercise, CO is at ? Of its maximum

Answer 20

90%

Question 21

At maximal exercise, pulmonary ventilation is at ? Of its maximum

Answer 21

65%

Question 22

At high altitude, oxygen molecules are farther apart so?

Answer 22

Decreases oxygenation

Question 23

At high altitude, its most important effect is?

Answer 23

Decreased mental proficiency

Question 24

High altitude: Coma and death at ? Feet

Answer 24

23,000 feet

Question 25

High altitude: Twitching and seizures at ? Feet

Answer 25

18,000 feet

Question 26

High altitude: Drowsiness, Lassitude, Mental & Muscle fatigue, Headache, Nausea, & Euphoria at ? Feet

Answer 26

12,000 feet

Question 27

Mechanisms of Acclimatization to Low PO2: Respiratory rate increases by 5x

Answer 27

Increased Pulmonary Ventilation

Question 28

Mechanisms of Acclimatization to Low PO2: Shift to the right of the O2-HgB dissociation curve

Answer 28

Polycythemia

Question 29

Mechanisms of Acclimatization to Low PO2: Increased pulmonary capillary blood volume, Increased lung volume, Increased pulmonary arterial BP

Answer 29

Increased Diffusing Capacity of Oxygen

Question 30

Mechanisms of Acclimatization to Low PO2: Cardiac Output increases by 30%

Answer 30

Increased vascularity of the Peripheral tissues

Question 31

Mechanisms of Acclimatization to Low PO2: Increased cell mitochondria and cellular oxidative enzymes

Answer 31

Increased ability of cells to use Oxygen despite low PO2

Question 32

Changes seen in natural acclimatization

Answer 32

Decreased body mass Increased chest size Larger hearts and lungs Better O2 delivery (increased HgB, better O2 utilization)

Question 33

Manifestations of Acute Mountain Sickness

Answer 33

Acute Pulmonary Edema | Acute Cerebral Edema

Question 34

Manifestations of Chronic Mountain Sickness

Answer 34

Pulmonary Vasoconstriction | Right-sided Heart Failure

Question 35

Adaptations to Flight: Pilot pushed against seat, more dangerous, blood shunted to the lower extremities

Answer 35

Positive G

Question 36

Adaptations to Flight: Pilot pushed against his seatbelt, less dangerous, blood shunted to the head

Answer 36

Negative G

Question 37

Motion sickness, Translocation of fluids, Diminished physical activity

Answer 37

Acute effects in Space

Question 38

Decreased blood volume, Decreased RBC, Decreased muscle strength, Decreased maximum cardiac output, Loss of calcium and phosphate from bones

Answer 38

Chronic effects in Space

Question 39

May lead to toxicities from high nitrogen, oxygen and carbon dioxide pressures

Answer 39

Diving

Question 40

High Nitrogen Pressures: "Raptures of the depths"

Answer 40

Beyond 250 feet

Question 41

High Nitrogen Pressures: Drowsiness

Answer 41

At 200-250 feet

Question 42

High Nitrogen Pressures: Joviality

Answer 42

At 120 feet

Question 43

Breathing oxygen at 4atm (PO2=3040mmHg) will cause sudden brain seizures followed by coma; Due to Oxygen Free Radicals (O2 and H2O2)

Answer 43

High Oxygen Pressure

Question 44

Happens only if diving apparatus has a malfunction; Severe respiratory acidosis, lethargy, narcosis

Answer 44

High Carbon Dioxide Pressure

Question 45

Sudden ascent a can lead to formation of nitrogen bubbles a blocks blood vessels

Answer 45

Decompression Sickness

Question 46

Pain in the joints and muscles

Answer 46

"Bends"

Question 47

Dyspnea

Answer 47

"Chokes"

Question 48

Chronic Decompression Sickness

Answer 48

Caisson's Disease